SOLUTION: Lala can remove the engine from a car in 4 hours. George can do it in 3 hours. George starts the job alone. One hour later, Lala begins helping him. How long will Lala work before
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: Lala can remove the engine from a car in 4 hours. George can do it in 3 hours. George starts the job alone. One hour later, Lala begins helping him. How long will Lala work before
Log On
Question 1032869: Lala can remove the engine from a car in 4 hours. George can do it in 3 hours. George starts the job alone. One hour later, Lala begins helping him. How long will Lala work before the engine is out? Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! George's rate of working: [ 1 engine removed ] / [ 3 hrs ]
In 1 hr, the fraction of the job that George gets done is:
That means 2/3 of the job is left to do
-----------------------
Lala's rate of working: [ 1 engine removed ] / [ 4 hrs ]
Now they work together to do the remaining 2/3 of the job
Let = their time in hrs to finish the job
Add their rates of working:
Multiply both sides by
and
Lala will work 1 hr 8 min 34 sec before engine is out
--------------------------
check:
OK
